Research And Analysis On Routing Protocols Of Wireless Sensor Networks

Wireless Sensor Network is a new and self-organized wireless network without complex infrastructure. With the development of microelectronics, sensor technology and telecommunication technology, wireless sensor networks develop rapidly, some successful application has been made in the military and civilian aspects. Because of its wide applications, wireless sensor networks have a bright future of development. Compared with traditional networks, sensor networks have the following features: A sensor network typically consists of a large number of nodes with a dense distribution. Each node is impossible to maintain global information. The nodes have very limited energy, storage space and computing ability. Wireless sensor networks usually work in high-risk regions and unable to get close, sensor nodes are likely to be battery powered, and it is often very difficult to change or recharge batteries for these nodes. Of these, energy efficiency for extending network lifetime is one of the most important topics. So it is important to study new routing protocols for wireless sensor networks to extend the lifetime of wireless sensor networks.This thesis introduces and summarizes wireless sensor networks, and primarily analyzing the classification, designing objective and impact factor of routing protocols, summarizing and comparing the typical routing protocols. Then, this thesis analyzes the principle and work process of LEACH (Low Energy Adaptive Cluster Hierarchy) protocol which is hierarchical-based routing in detail. LEACH is a wireless protocol that is distributed type. The nodes in this protocol which is the same with wide scale wireless sensor networks are greatly self-adaptive and fault-tolerant. But this protocol adopts the method of randomly judge the cluster head, ignoring the remaining energy of nodes, so there is limitation about protracting life-time of networks. So in this paper, LEACH-NEW, a new routing protocol which is improved is proposed.LEACH-NEW adopts the mode which is combined with distributed and centralized type, improved cluster choosing arithmetic. This protocol has the characters of LEACH, and has the better performance on protracting life-time of networks, data received by base station and keeping optimal number of cluster head.This thesis simulates LEACH and LEACH-NEW on the networks simulator platform named NS2. Based on the result of simulating, proving the superiority of LEACH-NEW.